Specifically, in my original design, I had Text comments in my ComboBox at load-up time, but then realised that users could type into the box, so I changed the DropDownStyle to DropDownList. Unfortunately, whilst this prevents the user from typing into the box, it also removes the Text from my VS2010 design and also ignores my C# updates to the Text in the program.
Is this normal behaviour or do I have a problem, or do I need to do this via another parameter ?
Keep your DropDownStyle on DropDown.
now on KeyPress event add the following:
e.Handled = true;
Related
Is it possible to make a ListBox ReadOnly? - Technically yes. Set the "Enabled" property to False.
Selection: None break my program because it's trying to select them from the program, but if a user selects one, I don't want it to change, or highlight. I want all highlighting done by the program, is this possible?
This picture shows what I have on my Form
My problem is, it works perfectly fine, I just want it nicer, by only allowing the user to click on only one of the selections from the red box, while they cannot select one from the blue boxes, but the computer can.
My assumption is that you are using WinForms, not WPF. So a simple way is to add a bool flag for each list control to your form. Then on the Selection changed event prevent the change from occurring unless you've set the bool to true. That will allow you turn on/off selected item changes.
Actually here is a link here, instead of bool just create an int to store the current index for each list box. Upon the Selection changing simply set the SelectedItemIndex to the int variable.
Cancelling ListBox SelectedIndexChange Event
I have the following problem with ComboBox (DropDownList). My settings for combo:
AutoCompleteMode: AutoCompleteMode.SuggestAppend
AutoCompleteSource: AutoCompleteSource.ListItems
DropDownStyle: ComboBoxStyle.DropDownList
This combobox have datasource from database.
`DisplayMember = "nombre";
ValueMember = "id";`
Now reproduction steps:
Focus and Popup (!) ComboBox, type for example 'dog' (at first element is selected 'ant' is selected, then 'dog' - which is fine) and then press Tab - Random value 'turtle' or anything is restored... no events of the value or index changed fired.. While debugging I see that on combobox Leave event value is still 'dog', but on DropDownClosed event it's switched back to 'turtle'. Nothing is fired in between.
I can´t understand why the combobox change text randomly but in debug mode still correctly.
I need when tab using autocomplete feature, the combobox still on value and text when im press tab.
PD: this happen only in combobox with datasource from database and the other computer LOL. in my workstation it's fine.
Solution:
http://support.microsoft.com/kb/2868238/en-us
It's O.S error, for previous versions of windows 7 SP1.
How to disable editing or hide text edit field, when DropDownStyle = Simple for Combo Box control?
MSDN on ComboBox.DropDownStyle:
The DropDownStyle property specifies whether the list is always displayed or whether the list is displayed in a drop-down. The DropDownStyle property also specifies whether the text portion can be edited.
Docs on ComboBoxStyle.Simple:
Specifies that the list is always visible and that the text portion is editable. This means that the user can enter a new value and is not limited to selecting an existing value in the list.
So, ComboBoxStyle.Simple suggests that list can be edited by user and it's confusing to disable edit with this DropDownStyle selected. Alternatives:
If you are ok with drop-down list use ComboBoxStyle.DropDownList
If you want to display a non-editable list with a view similar to ComboBoxStyle.Simple consider using ListBox
If you really need to achieve this effect on Combox you can just catch the events like "TextChanged" and then setting it back to "" and asking if (!comboBox1.DropDownStyle == ComboBoxStyle.Simple) before adding items to Items collection. Although it seems there are better ways to achive similar functionality using listbox as suggested before.
I have a custom control based on the label control. My question is how I disable the selection box around this custom control when a user selects it while in design mode.
I would like to just change the font color when selected, and then change it back when unselected.
The reason for this is because when you have many labels with small font very close together it makes it hard to see the other labels when you select one of them and the selection box from the one selected obscures the user from seen the other labels that are very close to the one selected.
You cannot prevent it from being selectable at design time. It is considered a component of the form and you will always be able to select it in order to be able to delete it or modify its properties by selecting it.
I have code that handles the LostFocus event of my controls. It validates the value and in some cases will enable a subsequent control. For instance, there might be a ComboBox that allows a user to select a country. The subsequent ComboBox allows the user to select a state. IF the currently selected country is not the USA, the state ComboBox is disabled. If the user selects "USA" and then tabs out of the combo box, the LostFocus code enables the state ComboBox. However, the State ComboBox does not get focus, instead focus goes to the control that follows the State ComboBox.
I've tried using the PreviewLostKeyboardFocus to handle the event instead with no luck. I'm kind of at a loss as to figuring out someway to hack WPF to get this work. Any suggestions?
try validating when the data changes, not the UI. You can add validation rules that will fire when the property is updated from the binding. Then you can use a style trigger to activate the control in question.
Check this article it should help.
I'm guessing what is happening is it determines the control to tab to before the LostFocus event fires, thereby skipping the State combo box since it is disabled. Here's the information for how focus works in WPF. What you will want to do is in your handler, determine if it should be going to the State combo box next, and programatically focus that element via the FocusManager class.